Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at January 13, 2016

Psoriasis is a common chronic, incurable skin disorder. The most common form of this disease is known as plaque psoriasis. Psoriasis often affects the scalp, legs, arms, and trunk, but it may also develop on any part of the body. Plaque psoriasis is characterized by elevated red skin plaques that are covered with itchy or burning scales.


Definition & Facts

Psoriasis is a common skin condition that alters the life cycle of the skin cells. It causes a rapid build-up of cells on the surface of the skin. These additional cells form thick, itchy, red dry patches and silvery scales that are at times painful. Psoriasis is a persistent, long-lasting malady. Sometimes it gets worse, and sometimes it improves.

The aim of treatment is to prevent the skin cells from multiplying rapidly. The disease has no cure, but treatment may provide significant relief to the patient. Lifestyle changes such as exposing the skin to reasonable amounts of light and application of nonprescription cortisone cream may improve the condition.

Symptoms & Complaints

Plaque psoriasis, sometimes referred to as psoriasis vulgaris, is the most prevalent form of this disease, and it usually produces plaques of red, scaly, raised skin that affects the elbows, knees, and scalp. These plaques may cause a burning sensation or itchiness. Psoriasis flare-ups may last for months or weeks. This disease can spontaneously resolve on its own and return later.

Psoriasis forms plaques of various sizes (one centimeter to several centimeters) that may be quite extensive or limited. The plaques may be round with irregular borders. Smaller plaques may merge, thus extending the affected area. The skin in the affected area, especially on the limbs and joints, may split and bleed. The plaques are sometimes surrounded by a ring or halo that can be noticed, especially after effective treatment when the lesions are resolving.

Additional symptoms include:

  • Red color—the color of the affected skin indicates an underlying inflammation, and it is caused by an increase in the blood flow
  • Scales—the scales formed during psoriasis are silvery white and thin, and their thickness may vary. After scales are pulled out, the underneath skin looks red, smooth and glossy. This skin usually has tiny bleeding pinpoint areas (Auspitz sign)
  • Symmetry—plaques appear symmetrically on both sides of the body, for instance, they are usually present on both elbows or knees
  • Nails—the nails often change. They may have pits or indentations. They can also be discolored and separated from the nail beds at the tip of the fingers. Their appearance is identical to fungal nail infections, and they may co-exist with or enhance the acquisition of fungal infection

Psoriasis in children looks a bit different from that in adults. In children, the plaque is not very thick, and the skin is not very scaly. It may often form in the diaper area for infants, and in the flexural areas in children. In children, it often affects the face.

The other areas that are most common for plaques include the scalp, arms, back, and legs. However, psoriasis can attack any other part of the body as well. Inverse psoriasis forms on the buttocks or genitalia, or under the arms or breasts, and it may not develop typical scales. These areas are usually itchy and have a burning sensation.


Psoriasis is a common disease, and it can affect anyone, but it usually begins at the age of 15 to 35. One cannot catch or spread the disease to others. Psoriasis seems to be genetic, and it is passed down through families. Doctors suspect it to be an autoimmune disease (when the immune system attacks and destroys good body tissues by mistake). Typically, the skin cells form deep within the skin, and they rise to the surface at a frequency of once per month. When someone has psoriasis, this process occurs very fast, and dead skin cells accumulate on the surface of the skin. The following factors trigger or make psoriasis more difficult to treat:

Psoriasis may become worse in individuals with a weak immune system that may be caused by AIDS, chemotherapy for cancer, autoimmune disorders like rheumatoid arthritis. Some people with psoriasis may also develop arthritis called psoriatic arthritis.

Diagnosis & Tests

The diagnosis of psoriasis is usually straightforward. It involves:

  • Physical exam and medical history—the physician can often diagnose the disease by the patient’s skin, nails, and scalp, and taking the patient’s medical history
  • Skin biopsy—occasionally, the doctor will take a biopsy (skin sample) and examine it under a microscope to determine the exact type of psoriasis. The biopsy also helps to rule out other conditions. The biopsy is done in the doctor’s office under local anesthesia. If the patient has joint pains, the doctor may order X-rays

Treatment & Therapy

The aim of treatment is to prevent infections and control the patient’s symptoms. The treatment options include:

  • Skin lotions, creams, shampoos, and ointments, also known as topical medication
  • Injections or pills that affect the body’s immune system and not just the skin. This form of treatment is known as systemic or body-wide treatment
  • Phototherapy—this involves the use of light to treat psoriasis

Prevention & Prophylaxis

Scientists are not sure of what causes psoriasis, and thus, there are no known preventive measures. However, prevention focuses on reducing the number of recurrences and severity of the disease. Thus, the patients are advised to:

  • Identify what triggers their psoriasis. The most well-known causes are drinking alcohol, smoking, stress, prolonged exposure to the sun, injuries on the skin, and infections. Avoiding these triggers as much as possible reduces the likelihood of experiencing flare-ups
  • Keep the skin moisturized—patients should use moisturizing creams, ointments, and lotions frequently, especially in dry weather
  • Take showers daily—good hygiene enhances the cell turnover and reduces the possibilities of developing plaques
  • Avoid scrubbing too vigorously—doing so may irritate the skin and cause the recurrence or worsening or the disease
  • Avoid certain medications—anti-malarial drugs, lithium (for depression) and beta-blockers (for high blood pressure) are known to aggravate the symptoms of psoriasis
  • Learn anti-stress and relaxation techniques—these are known to prevent the recurrence of the disease or suppress the symptoms during a flare. Up to 80 percent of patients with flare-ups report recent emotional traumas such as the death of a loved one

Psoriasis is an incurable disease that can be treated topically, using injections and pills, and phototherapy. And the patients are advised to live a healthy lifestyle to prevent the worsening of symptoms.